摘要阐述了基于RF MEMS技术的可调式复合左右手传输线单元的设计。复合左右手
传输线单元的设计包括Interdigital Capacitor和Stub Inductor的设计， 以在
基本的传输线结构上增加除本征的串联电感和并联电容之外的串联电容和并联电
感。采用CST微波工作室和AWR2009仿真，我们实现了在8GHz, 9GHz, 10GHz, 11GHz
和12GHz 5个频点的平衡的复合左右手传输线单元的设计。仿真结果显示该结构能
很好的达到平衡传输线的要求。除此之外，通过MATLAB编程绘制色散曲线，进一
步验证了传输线的特性。通过级联3个CRLH传输线单元，我们得到了零阶谐振器的
设计，进一步测试了左右手传输线的特性。为了增加传输线的可调节性能，同时
保持阻抗匹配和结构平衡，我们在所设计的电容和电感中引入RF MEMS开关。通过
验证，开关能在on状态有较高的隔离度，off状态有较小的插入损耗 。最后文章
建立了基于RF MEMS开关的可调型传输线单元模型，通过开关调节电容和电感值可
以完成不同状态的切换。4944
关键词 RF MEMS开关 叉指电容 电感 色散曲线 S参数
Abstract
This project focuses on designing a novel tunable composite right/left-handed
transmission line (CRLH TL) using integrated microelectromechanical system
(MEMS) switches. One unit cell of CRLH TL has been developed and simulated
by EM solvers in this article, which consists of design of interdigital
capacitors and stub inductors to add additional series capacitance and shunt
inductance. The structure is analyzed using CST Microwave Studio (MWS) and
AWR2009. We realized the balanced unit cell of CRLH TL at the frequency point
of 8GHz, 9GHz, 10GHz, 11GHz and 12GHz. In addition, dispersion curves of the
unit cells are generated by MATLAB2010 to verify the characterization of the
CRLH TL. Furthermore, zero order resonator made up of three cells of CRLH TL
is constructed to further testify the characteristic of the unit cell of CRLH
TL. In a novel approach, RF MEMS Switches with high reliability are designed
and tested. Models of tunable unit cell is set up which implements the RF MEMS
switch to add to the capacitors and inductors to make the frequency range
tunable, while the line impedance is still matching and the structure balanced
during tuning. By testing in CST and AWR, it is proved that the switch has
high isolation at on state and low insertion loss at off state. The different
states are determined by controlling the admittance of capacitors and
impedance of inductors through MEMS switch operations.
Keywords RF MEMS Switch Interdigital Capacitor Inductor
Dispersion Curve S-parameterContent
1 Introduction 1
1.1 Background of the Project 1
1.2 Introduction of the Design 2
2 Basic Theory . 3
2.1 Composite Right/left-handed Transmission Line . 3
2.2 Interdigital Capacitor and Stub Inductor 7
2.2.1 Interdigital Capacitor 8
2.2.2 Stub Inductor . 9
2.3 RF MEMS Switch 10
2.3.1 The Structure and Reliability of RF MEMS Switch . 10
2.3.2 IDC and RS with RF MEMS Switches . 12
2.4 Dispersion Diagram 14
3 Design of Tunable CRLH TL . 15
3.1 General Analysis of the Project 15
3.2 Design of Interdigital Capacitor and Stub Inductor . 16 Design of RF MEMS Based Tunable Cell for CRLH Transmission Line:http://www.youerw.com/yingyu/lunwen_1769.html